In vitro assessment of rhesus monkey (Macaca mulatta) luteal cell function was further extended utilizing dissociated cells from the corpus luteum. The main topics of interest in this project have included: 1) morphological and functional correlations of luteal cells maintained in culture for ten days, 2) effects of non-gonadotropin hormones and cholesterol on the maintenance of functional luteal cells, 3) evaluation of progesterone production by dissociated luteal cells after brief exposure to trypsin, and 4) localization of LH/hCC receptors of dissociated luteal cells.